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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-05-08 19:50:20 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-05-14 11:29:48 +0200 |
| commit | 8c414ff3f4dcdde228c6a668385218290d73a265 (patch) | |
| tree | 2454fc7bf7d76b13fd6c03c08954afbae9d633b0 | |
| parent | clocksource: add common i8253 PIT clocksource (diff) | |
| download | linux-8c414ff3f4dcdde228c6a668385218290d73a265.tar.xz linux-8c414ff3f4dcdde228c6a668385218290d73a265.zip | |
clocksource: convert footbridge to generic i8253 clocksource
Convert the footbridge isa-timer code to use generic i8253 clocksource.
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/i8253.h | 15 | ||||
| -rw-r--r-- | arch/arm/mach-footbridge/Kconfig | 2 | ||||
| -rw-r--r-- | arch/arm/mach-footbridge/isa-timer.c | 45 | ||||
| -rw-r--r-- | include/linux/clocksource.h | 2 |
4 files changed, 23 insertions, 41 deletions
diff --git a/arch/arm/include/asm/i8253.h b/arch/arm/include/asm/i8253.h new file mode 100644 index 000000000000..70656b69d5ce --- /dev/null +++ b/arch/arm/include/asm/i8253.h @@ -0,0 +1,15 @@ +#ifndef __ASMARM_I8253_H +#define __ASMARM_I8253_H + +/* i8253A PIT registers */ +#define PIT_MODE 0x43 +#define PIT_CH0 0x40 + +#define PIT_LATCH ((PIT_TICK_RATE + HZ / 2) / HZ) + +extern raw_spinlock_t i8253_lock; + +#define outb_pit outb_p +#define inb_pit inb_p + +#endif diff --git a/arch/arm/mach-footbridge/Kconfig b/arch/arm/mach-footbridge/Kconfig index bdd257921cfb..46adca068f2c 100644 --- a/arch/arm/mach-footbridge/Kconfig +++ b/arch/arm/mach-footbridge/Kconfig @@ -4,6 +4,7 @@ menu "Footbridge Implementations" config ARCH_CATS bool "CATS" + select CLKSRC_I8253 select FOOTBRIDGE_HOST select ISA select ISA_DMA @@ -59,6 +60,7 @@ config ARCH_EBSA285_HOST config ARCH_NETWINDER bool "NetWinder" + select CLKSRC_I8253 select FOOTBRIDGE_HOST select ISA select ISA_DMA diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c index 441c6ce0d555..7020f1a3feca 100644 --- a/arch/arm/mach-footbridge/isa-timer.c +++ b/arch/arm/mach-footbridge/isa-timer.c @@ -10,53 +10,16 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/io.h> +#include <linux/spinlock.h> #include <linux/timex.h> #include <asm/irq.h> - +#include <asm/i8253.h> #include <asm/mach/time.h> #include "common.h" -#define PIT_MODE 0x43 -#define PIT_CH0 0x40 - -#define PIT_LATCH ((PIT_TICK_RATE + HZ / 2) / HZ) - -static cycle_t pit_read(struct clocksource *cs) -{ - unsigned long flags; - static int old_count; - static u32 old_jifs; - int count; - u32 jifs; - - raw_local_irq_save(flags); - - jifs = jiffies; - outb_p(0x00, PIT_MODE); /* latch the count */ - count = inb_p(PIT_CH0); /* read the latched count */ - count |= inb_p(PIT_CH0) << 8; - - if (count > old_count && jifs == old_jifs) - count = old_count; - - old_count = count; - old_jifs = jifs; - - raw_local_irq_restore(flags); - - count = (PIT_LATCH - 1) - count; - - return (cycle_t)(jifs * PIT_LATCH) + count; -} - -static struct clocksource pit_cs = { - .name = "pit", - .rating = 110, - .read = pit_read, - .mask = CLOCKSOURCE_MASK(32), -}; +DEFINE_RAW_SPINLOCK(i8253_lock); static void pit_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) @@ -121,7 +84,7 @@ static void __init isa_timer_init(void) pit_ce.max_delta_ns = clockevent_delta2ns(0x7fff, &pit_ce); pit_ce.min_delta_ns = clockevent_delta2ns(0x000f, &pit_ce); - clocksource_register_hz(&pit_cs, PIT_TICK_RATE); + clocksource_i8253_init(); setup_irq(pit_ce.irq, &pit_timer_irq); clockevents_register_device(&pit_ce); diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index c37b21ad5a3b..f13469b3df86 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -341,4 +341,6 @@ static inline void update_vsyscall_tz(void) extern void timekeeping_notify(struct clocksource *clock); +extern int clocksource_i8253_init(void); + #endif /* _LINUX_CLOCKSOURCE_H */ |